Saudi Arabian officials say Saudi troops have entered the neighboring island state of Bahrain to help its minority Sunni rulers boost security after weeks of anti-government protests.

Witnesses told the Reuters news agency that about 200 Saudi military vehicles crossed a causeway that joins the two nations early Monday. It was not immediately clear where the troops were heading. Gulf News reported that foreign troops from neighboring Gulf nations would be guarding government installations.

Bahraini opposition groups issued a statement denouncing the Saudi move, calling it an occupation of their nation.

A Saudi official said the Saudi troops are part of a regional force set up by the six-nation Gulf Cooperation Council. There was no immediate confirmation from Bahrain's government. But a Bahraini newspaper linked to the ruling al-Khalifa family reported Monday that a GCC force was expected to arrive in the country.

Earlier, pro-government Bahraini lawmakers urged the government to impose martial law to put an end to a month of protests by majority Shi'ites demanding a greater political voice in the country's affairs. The state-run Bahrain News Agency said the lawmakers want King Hamad bin Issa al-Khalifa to enforce martial law for three months to protect peace and stability.

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